Prelab Complete

Labs/Lab06/Makefile

+all: collatz
+CC=gcc
+CFLAGS=-Wall -Werror
+
+collatz: collatz.o
+	$(CC) $(CFLAGS) collatz.o -o collatz

Labs/Lab06/collatz.c

+#include <stdio.h>
+#define MAX_ITEMS 100
+
+int collatz(int n)
+{
+	if (n == 1){
+		return n;
+	}
+ 	if (n%2 == 0){
+		return n/2;
+	}
+	if (n%2 == 1){
+		return 3*n+1;
+	}
+	return 0;
+}
+
+int find_length(int n)
+{
+	int count = 0;
+	if (n == 1){
+		count = 1;
+		return count; 
+	}
+	else{
+		count = 1;
+		while (n > 1){
+			count++;
+			n = collatz(n);
+		}
+		return count;
+	}
+	
+}
+
+int main(void)
+{
+    int i;
+
+    for (i = 1; i < MAX_ITEMS; i ++){
+        printf ("%d ==> %d\n", i, find_length(i));
+    }
+
+    return 0;
+}

Labs/Lab06/prelab.s

+# File: prelab.s
+
+# CSCI 206
+
+# Lab 06
+
+# Spring 2020
+
+# Originally by Professor Guattery and Professor Meng in spring 2011
+
+# Revised: Xiannong Meng
+
+# 02/20/2016
+
+# 2019-11-04 for RISC-V
+
+#
+
+# Student name:
+
+#
+
+# This simple program demonstrates writing very simple leaf procedures.
+
+# The program computes an expression in the form of "4x - (2y + C)".
+
+# You are to the procedure "myFunc", taking two parameters (x and y) and
+
+# produce "4x - (2y + C)" within the procedure.
+
+# See detailed instructions in lab handout.
+
+
+
+	.data
+
+# Define the constant c here
+
+C:	.word	1
+
+
+
+	.text
+
+# The main() procedure calls my_func twice, storing the results into s0 and s1
+
+main:
+
+	# Call my_func(2, 3) storing result in s0 [s0 = 4*2 - (2*3 + 1) = 1]
+
+	addi	a0, zero, 2		# load 2 (x) into a0
+
+	addi	a1, zero, 3		# load 3 (y) into a1
+
+	jal	my_func
+
+	add	s0, zero, a0		# store result in s0
+
+
+
+	# Call my_func(5, 6) storing result in s1 [s1 = 4*5 - (2*6 + 1) = 7]
+
+	addi	a0, zero, 5
+
+	addi	a1, zero, 6
+
+	jal	my_func
+
+	add	s1, zero, a0
+
+
+
+	#
+
+	# Add code here to print the result of my_func(2,3) + my_func(5,6)
+
+	#
+	add    a0, s1, s0
+	li     a7, 1
+	ecall
+
+		
+
+	# The program is finished. Tell the "Operating System" that we wish to exit.
+
+	# We'll learn more about this syntax later this week
+
+	addi	a7, zero, 10		# system call for exit
+
+	ecall
+
+
+
+# my_func = 4x - (2y + C)
+
+# Because this function modifies only a0, there is no need
+
+# to create an activation frame
+
+my_func:
+
+#
+
+# your code for the procedure goes here 
+
+#
+	li      s3, 0
+ 	li      t0, 4
+ 	li      t1, 2
+ 	la      t5, C
+ 	lw      s3, 0(t5)
+	mul     t2, t0, a0
+	mul     t3, t1, a1
+	add     t4, t3, s3
+	sub     t6, t2, t4
+	mv      a0, t6
+
+    jr ra
+    
+#0040000C - Line 55
+
+#0040001C - Line 67
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